<!--
  Copyright 2020 The Chromium Authors. All rights reserved.
  Use of this source code is governed by a BSD-style license that can be
  found in the LICENSE file.
-->
<style>
  #focus:not(:focus) .show-on-focus {
    display: none;
  }

  #focus {
    background-color: rgba(0, 128, 0, 1);
  }
</style>
<div id="focus" tabindex="0">
  <span>Some text with a green background once focused</span>
  <span class="show-on-focus">Some text here, only shown on hover</span>
</div>
